public class NewClass4 {
    public static void main(String[] args)
    {
        HashMap<Integer,Integer>map=new HashMap<Integer, Integer>();
        map.put(1, 50);
        map.put(2, 60);
        map.put(3, 30);
        map.put(4, 60);
        map.put(5, 60);
        int maxValueInMap=(Collections.max(map.values()));  // This will return max value in the Hashmap
        for (Entry<Integer, Integer> entry : map.entrySet()) {  // Itrate through hashmap
            if (entry.getValue()==maxValueInMap) {
                System.out.println(entry.getKey());     // Print the key with max value
            }
        }

    }
}

fun max(map:Map<Int,String>) =  map.maxByOrNull { it.key }?.key ?:-1//returns negative one if the max is null
fun main(){
var map = mapOf(1 to "hello",2 to "peace", 3 to "ochuko")
    println(map.maxByOrNull { it.key }?.key ?:-1)
}

//For kotlin
fun max(map:Map<Int,String>) =  map.maxByOrNull { it.key }?.key ?:-1//returns negative one if the max is null
fun main(){
var map = mapOf(1 to "hello",2 to "peace", 3 to "ochuko")
    println(map.maxByOrNull { it.key }?.key ?:-1)
}